There are certain strains made specifically for these purposes that have low 'high-inducing' THC, but high 'therapeutic' CBD. These are typically the canna oils used in children to lessen seizure activity, etc. One such strain, Charlotte's Web, was named after the little girl it was created for. I don't know if those strains are good for cancer treatment, but it's absolutely worth looking into. This plant deserves much more respect then the medical community gives it. We haven't yet tapped into its full potential. Good luck and be well!